A VICTORIAN TWO-DAY ROYAL OBSERVATORY MARINE CHRONOMETER WITH AIRY'S BAR AND DENT'S "PRISMATIC" BALANCE

細節

A VICTORIAN TWO-DAY ROYAL OBSERVATORY MARINE CHRONOMETER WITH AIRY'S BAR AND DENT'S "PRISMATIC" BALANCE
Dent, No. 2983, circa 1861

The silvered dial signed and numbered DENT, LONDON, CHRONOMETER MAKER TO THE QUEEN, No. 2983, WITH AIRY'S SUPPLEMENTARY COMPENSATION and the Government Mark, subsidiary seconds and up-and-down dials, blued steel hands, the top plate incised with the Government Mark, Earnshaw escapement, Dent's cut bimetallic "prismatic" balance with Airy's compensation bar, polished steel helical balance spring, circular heat compensation weights, spring foot detent with jewelled locking stone, "stop/start" assembly (not functioning) operated through the bottom of the brass bowl, gimballed in plain three-tier mahogany box, centre section with bone ivory disc inscribed DENT 2983 TWO DAYS and with the Government Mark, inside the top lid a large engraved trade label of E. DENT & CO. LTD., external brass drop handles, the tipsy key numbered 2983
92mm. dial diam., 172mm. sq. box

拍品專文

The present chronometer was not entered in any of the Greenwich Chronometer Trials between 1860 and 1874. It would appear that it was purchased 'without trial' in February 1873.
In 1873 it was issued for use at Deal in connection with the Deal time-ball. The Deal time-ball came into operation on Monday 1 January 1855 and was dropped by the 1 p.m. electric circuit that dropped the Greenwich time-ball. It was in continuous use until 1927.
In 1878 No. 2983 was issued to H.M. Survey Ship ALERT, Captain Sir George S. Nares, KCB, FRS, R.N. and was used in that ship's surveys of the Magellan Strait and the River Plate.
In 1879 Nares passed over the command of Alert to Captain J.F.L.P. Maclear R.N. and for the next three and a half years the South American survey work continued and later surveys of the Indian Ocean and Australia were progressed.
In 1895 the present chronometer was issued to H.M. Survey Ship WATERWITCH, Lieutenant J.W. Combe, R.N. and during the next three years it was used in the surveys of the Fiji Islands in preparation of the laying of telegraph cables. Subsequently it was used in the surveys of the Tasman Peninsula, Tasmania, and of Esperance Bay on the south west coast of Australia.
No. 2983 continued in service with the Royal Navy until 1922.